The advent of deoxyribonucleic acid (DNA) microarray, or DNA chip, technology makes it possible to build an array of hundreds of thousands of DNA sequences in a very small area. A maskless array synthesizer (MAS) instrument uses light to direct synthesis of the DNA sequences. The array probes (e.g., a combination of a universal primer, a sequence-specific probe, and optionally a calibrated probe sequence) are synthesized one nucleotide at a time in the common area of the microarray using the MAS instrument. Graphics files that describe the pattern of light used to synthesize the DNA sequences are used to create a series of virtual masks. The “virtual masks” are formed by digitally addressing a micromirror array using the graphics files in synchrony with the synthesis chemistry to synthesize the DNA chip. The widespread use of DNA microarray chips is still limited, however, by their relatively high cost. For large-scale studies, the cost per feature rather than the cost per chip is important. Therefore, what is needed is a system and a method that increase the number of features per chip to reduce the cost per feature.